Seam joining together at least two web materials

ABSTRACT

A seam joining together at least two web materials in an overlapped manner, wherein the overlapped portions are bonded together by ultrasonic welding, heat bonding, laser welding or the like, in a bonding pattern extending over at least a part of the overlapped portion to form said seam. The bonding pattern has a main bonding pattern extending in longitudinal direction along at least a part of the overlapped portion, and at least one edge bonding pattern extending in longitudinal direction along at least a part of along and adjacent at least one side edge of the overlapped portion, the bonded area of said edge bonding pattern occupying no more than 30% of the total bonded area of the central bonding pattern plus the bonded area of the edge bonding pattern. The seam may be present in a personal care absorbent article.

PRIORITY

This application is a national stage application of PCT/SE2006/000858,filed 13 Jul. 2006.

TECHNICAL FIELD

The present disclosure refers to a seam joining together at least firstand second web materials, at least one of which comprising heat fusiblematerial, the first web material having a side edge overlapping with aside edge of the second web material, wherein an overlapped portion isformed where said web materials overlap. The web materials in saidoverlapped portion are bonded together by ultrasonic welding, heatbonding, laser welding or the like, in a bonding pattern extending overat least a part of the overlapped portion to form said seam.

BACKGROUND

Web materials comprising heat fusible material, either fibrous webs,films or laminates thereof, are used in a variety of applications, suchas protective clothing and hygiene articles, especially disposableabsorbent personal care articles, like diapers, sanitary napkins andincontinence guards. In most of such applications the web materials mustbe joined, which is conventionally done by ultrasonic welding, heatbonding, laser welding or by adhesive. Bonding by ultrasonic welding,heat bonding or laser welding is usually done by forming a bondingpattern comprising a plurality of bonding sites in which the heatfusible components of the web materials are fused and thus bondedtogether.

The bonding is done in a process line, in which material variations aswell as process variations may occur, which can effect the exactpositioning of the bonding pattern with respect to the overlapping sideedges of the web materials. If the bonding pattern ends up being locateda bit offset with respect to the overlap, an edge of the overlap mayprotrude from the surface of the joined web materials. This will reducethe quality of the seam and of the article and if used in an articleworn against the skin of a wearer such a protruding edge may cause skinirritations.

U.S. Pat. No. 5,919,539 discloses ultrasonic seaming of spunbondedpolyolefin sheets for example used in protective clothing. Theoverlapping sheet edges are fed between an ultrasonic horn and apatterned roll that has a raised pattern corresponding to the desiredbonding pattern. A waffle-like bonding pattern is created and the edgesof the sheet are welded over so as to eliminate protruding sheet edgesalong the seam.

U.S. Pat. No. 5,626,574 refers to a disposable diaper having a front anda back body panel bonded to each other by ultrasonic welding to formside seams. The welded side seams are defined by patterns ofintermittently arranged bonding sites of different shape. The purpose isto create a welding pattern which allows the side seams to be torn openlongitudinally along the welded zones.

U.S. Pat. No. 4,938,817 shows a welding pattern for joining twooverlapping material webs, said welding pattern comprises short dashedlines extending in parallel to the edges of the fabric.

U.S. Pat. No. 4,205,679 discloses a disposable undergarment in which astrong ultrasonic weld seam is formed by a plurality of weld linesextending in longitudinal direction of the overlapping side edges spacedinwardly from the edges of the overlap.

There is a need for an improved bonding pattern for seams joiningtogether at least two web materials of the above mentioned kind, saidbonding pattern providing both a strong seam along the overlap and areduced risk for protruding edges along the seam

OBJECT AND SUMMARY

The present disclosure aims at solving the problem set out above andsuggests that said bonding pattern comprises a main bonding patternextending in longitudinal direction along at least a part of theoverlapped portion, and at least one edge bonding pattern extending inlongitudinal direction along and adjacent at least a part of at leastone of said side edges, the bonded area of said edge bonding pattern(s)occupying no more than 30% of the total bonded area of the main bondingpattern plus the bonded area of the edge bonding pattern(s).

This means that the area occupied by bonding sites in the edge bondingpattern(s) should be no more than 30% of the total area occupied bybonding sites in the edge bonding pattern(s) plus the main bondingpattern.

The main bonding pattern provides for a strong seam along the overlap,while the edge bonding pattern bonds down the side edges along theoverlap. Due to the limited bonding area of the side edge bondingpattern the softness and flexibility in this region of the seam issubstantially maintained.

In one embodiment said edge bonding pattern occupies at least 5%,preferably at least 7% of the total bonding area occupied by thecombined central bonding pattern and edge bonding pattern.

In a further aspect said edge bonding pattern occupying no more than 25%of the total bonding area occupied by the combined central bondingpattern and edge bonding pattern.

The edge bonding pattern may be in the form of a plurality of smallbonding sites each having an area of no more than 4 mm².

The central bonding pattern is defined in longitudinal direction, y, byan outer limiting margin and the edge bonding pattern is defined inlongitudinal direction, y, by an inner limiting margin, wherein in oneembodiment the distance between said outer and said inner limitingmargin is at least 1.5 mm.

According to one embodiment said bonding pattern comprises two edgebonding patterns, one on each side of the central bonding pattern.

The distance between the inner limiting margins of the two edge bondingpatterns is in one embodiment between 25 and 95%, preferably between 30and 80% of the width of the seam in transverse direction, x.

The width of the seam in transverse direction, x, is in according to oneaspect of the disclosure between 8 and 30 mm.

The main central bonding pattern has according to one embodiment abonding density of between 10 and 80%, preferably between 20 and 60%.The edge bonding pattern has according to a further embodiment a bondingdensity of at least 2% and no more than 60%, preferably no more than 50%and more preferably no more than 30%.

“Bonding density” is herein defined as the area occupied by bondingsites in relation to the entire area circumscribed by the bondingpattern including the non-bonded areas between bonding sites.

In one aspect of the disclosure the web materials have a basis weightbetween 25 and 130 g/m².

In a further aspect of the disclosure at least one of the web materialsis an elastic material.

In a still further aspect the seam is present in a personal careabsorbent article comprising an absorbent structure and first and secondweb materials comprising heat fusible material joined together to formsaid seam.

The personal care absorbent article is in one embodiment a pant-likegarment comprising a first body panel, a second body panel and a crotchportion there between, said first and second body panels being joinedtogether in an overlapped manner by a bonding pattern as described toform side connections forming said seam.

In a further embodiment the personal care absorbent article is apant-like garment comprising a first body panel, a second body panel anda crotch portion there between, said first and second body panels beingjoined together to form side connections and further being provided withan elastic waistband, said waistband being joined to the first and/orsecond body panels in an overlapped manner by a bonding pattern asdescribed to form said seam.

In a still further embodiment the personal care absorbent article is anabsorbent garment such as a diaper and an incontinence guard comprisinga first body panel, a second body panel and a crotch portion therebetween, each of said first and second body panels having a waistportion, said garment further being provided with opposed laterallyextending belt members attached to the waist portion of the first bodypanel and being adapted to be wrapped around the waist of the wearer ofthe garment and fastened together by means of first fastening means, thesecond body panel at its waist portion being provided with secondfastening means adapted to be fastened to the belt members, in such away that the garment will assume a pant-like shape, said belt membersbeing joined to first body panel in an overlapped manner by a bondingpattern as described to form said seam.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will in the following be closer described with referenceto some embodiments shown in the accompanying drawings. It should befurther understood that the drawings are not necessarily drawn to scaleand that, unless otherwise indicated, they are merely intended toconceptually illustrate the structures described herein.

FIG. 1 a shows a schematic side view of a welded seam between twooverlapping web materials.

FIG. 1 b is a corresponding view showing a bonding pattern which isnarrower than the overlap between the webs.

FIG. 2 a shows a schematic side view of an ultrasonic welding equipmentgenerating a weld seam between two overlapping web materials.

FIG. 2 b is a corresponding view showing the ultrasonic equipmentlocated a bit offset with respect to the overlap between the webmaterials.

FIG. 3 a is a plan view of two overlapping web materials bonded with abonding pattern according to an embodiment of the disclosure.

FIG. 3 b is a corresponding view but showing the bonding pattern a bitoffset with respect to the overlap.

FIGS. 4 a and b are plan view of two overlapping web materials bondedwith alternative bonding patterns.

FIG. 5 is a perspective view of a pant-type absorbent article.

FIG. 6 is a plan view of a belted diaper.

FIG. 7 shows on a larger scale a detail from FIG. 6, namely theattachment of the belt to the article.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIGS. 1 a and b illustrate schematically two overlapping web materials 1and 2 at least one of which comprising heat fusible material. The websmay be a fibrous nonwoven material, a plastic film or laminates thereof.The overlapped portion between the two webs is denoted with the numeral3. The webs 1 and 2 are in the overlapped portion joined by a bondingpattern 4 comprising a plurality of bonding sites. The bonding isaccomplished by any method known in art in which the heat fusiblematerial is caused to melt and thus bond the webs 1 and 2 together, forexample ultrasonic welding, heat bonding, laser welding or the like. Thethus bonded overlapped portion forms a seam joining together the two webmaterials 1 and 2. The seam is located in the same plane as the two webmaterials. Both webs have portions extending outside the overlap.

In FIG. 1 a the overlapped portion 3 is rather narrow and the bondingpattern 4 extends over the entire width of the overlapped portion. Thusthe respective side edges 1 a and 2 a of the two web materials arelocated close to the edges of the bonding pattern 4. This is anappealing look for a seam, but difficult to achieve in a process linerunning at high speeds.

It is favourable to have both web materials 1 and 2 covering the entirebonding pattern 4. If the bonding pattern 4 extends outside theoverlapped portion 3, no bonding will occur in this region which meansthat the bonding area gets smaller and the energy level increases in theactual bonding area, which may cause burn through of the material.

FIG. 1 b shows an overlapped portion 3 that is wider than the width ofthe bonding pattern 4. Thus the edges 1 a and 2 a of the web materialsextend beyond the edges of the bonding pattern. This is easier toachieve in a process line, but not as appealing as the seam in FIG. 1 a,since the web material side edges 1 a and 2 a will protrude from theplane of the web materials.

FIGS. 2 a and 2 b are schematic side views of an ultrasonic weldingequipment comprising an ultrasonic horn 5 and an anvil roll 6 with apattern of protuberances 7 for generating the bonding pattern. A pair ofoverlapping web materials 1 and 2 passes in the gap between theultrasonic horn 5 and the anvil roll 6 to be ultrasonically weldedtogether. The ultrasonic energy causes the portions of the web materialsthat are pressed against the horn 5 to momentarily melt and thus bondthe web materials together in the area where the protuberances 7 on theanvil roll 6 presses the material against the horn 5. If, as shown inFIG. 2 b, the pattern of protuberances 7 generating the bonding patternextend outside the overlapped portion of the two web materials thebonding area decreases resulting in an increase of ultrasonic energy perunit bonding area. As discussed above this may result in burn through ofthe web materials.

Thus there is a problem to achieve a high quality seam between webmaterials in a process line running at high speed and in which smallvariations in the width of the overlapped portions and/or the exactlocation thereof may occur.

The present disclosure aims at suggesting a bonding pattern which isless sensitive to such process variations and which provides a highquality seam even if the bonding pattern may end up slightly offset withrespect to the overlapped portions of the web materials.

An example of a bonding pattern according to the disclosure is shown inFIGS. 3 a and b. The bonding pattern 4 comprises a main bonding pattern8 extending in longitudinal direction, y, centrally along the overlappedportions 3 and edge bonding patterns 9 extending in longitudinaldirection along both sides of the main bonding pattern 8 adjacent therespective side edge 1 a and 2 a of the web materials. In an alternativeembodiment only one edge bonding pattern 9 is provided, in which casethe main bonding pattern 8 may be located offset with respect to thelongitudinal center of the overlapped portion 3, closer to the oppositeside edge having no edge bonding pattern 9.

The main bonding pattern 8 occupies a larger bonding area than the edgebonding pattern(s) 9, such that the edge bonding pattern(s) 9 occupy nomore than 30%, preferably no more than 25% of the total bonding areaoccupied by the combined main bonding pattern 8 and edge bondingpatterns 9. As mentioned above this means that the area occupied bybonding sites in the edge bonding pattern(s) 9 should be no more than30% of the total area occupied by bonding sites in the edge bondingpattern(s) 9 plus the main bonding pattern.

In case of two edge bonding patterns, one on each side of the mainbonding pattern, it is further preferred that the edge bonding patternsoccupy at least 5%, preferably at least 7% of the total bonding areaoccupied by the combined central bonding pattern and edge bondingpatterns. If only one edge bonding pattern is provided it is preferredthat the edge bonding pattern occupies between 2 and 20% of the totalbonding area occupied by the combined central bonding pattern and edgebonding pattern.

The main bonding pattern 8 has longitudinal outer limiting margins 8 aon either sides, said margins 8 a being tangents to the main bondingpattern along its opposite sides. The respective edge bonding pattern 9has a longitudinal inner limiting margin 9 a, said margin being atangent to the edge bonding pattern 9 along the side thereof facing themain bonding pattern 8. The distance between the outer limiting margin 8a of the main bonding pattern 8 and the respective edge bonding pattern9 is in FIG. 3 a denoted with a. The distance a is preferably at least1.5 mm.

The distance between the inner limiting margins 9 a of the two edgebonding patterns is preferably between 25 and 95%, preferably between 30and 80% of the width of the overlapped portion 3 in transversedirection, x.

The main bonding pattern 8 has preferably a bonding density of between10 and 80%, preferably between 20 and 60%, while the edge bondingpatterns have a bonding density of at least 2% and no more than 60%,preferably no more than 50% and more preferably no more than 30%.

The bonding density is defined as the area occupied by bonding sites inrelation to the entire area circumscribed by the bonding patternincluding the non-bonded areas between bonding sites.

FIGS. 4 a and b show examples of alternative bonding patterns accordingto the disclosure.

The edge bonding pattern 9 is preferably in the form of a plurality ofsmall bonding sites, such as dot, lines or the like, each having an areaof no more than 4 mm². The main bonding pattern 8 may comprise largerbonding sites or alternatively a plurality of small bonding sites,located denser than the bonding sites of the edge bonding patterns 9.

The main bonding pattern 8 provides for a strong seam along theoverlapped portion 3, while the edge bonding patterns 9 bond down theside edges 1 a, 2 a which extend laterally beyond the edges of the mainbonding pattern. Due to the limited bonding area of the side edgebonding pattern the softness and flexibility in this region of the seamis substantially maintained.

In FIG. 3 b it is shown a bonding pattern 4 located slightly offset withrespect to the overlapped portion 3. The main bonding pattern 8 ishowever located within the overlapped portion and only part of one edgebonding pattern 9 has ended up laterally outside the overlapped portion.The quality of the seam will still be high since the minor part of thebonding pattern located outside the overlapped portion 3 will decreasethe bonding area only to a minor extent, thus resulting in only a minorincrease of the ultrasonic energy per unit bonding area.

The width of the bonding pattern in transverse direction, x, can be madesubstantially equal to or only slightly smaller than the width of theoverlapped portion 3 in transverse direction. This means that it isprevented that the side edges 1 a and 2 a of the web materials 1 and 2protrude from the plane of the web materials, but are bonded down by theedge bonding patterns 9.

The bonding pattern according to the disclosure is less sensitive thantraditional bonding patterns to process variations which may cause thebonding pattern to end up slightly offset with respect to thelongitudinal center of the overlapped portion 3.

The disclosure is especially applicable on web material having a basisweight between 25 and 130 g/m². At least one web material is in oneembodiment of the disclosure an elastic material, such as an elasticfilm, an elastic nonwoven or an elastic laminate therefrom. An elasticmaterial is defined as a material having an elasticity of at least 30%in the elasticity test described below.

The width of the overlapped portion 3 in transverse direction, x, ispreferably between 8 and 30 mm.

One important application of the disclosure is in personal careabsorbent articles such as diapers, incontinence guards, sanitarynapkins and the like comprising an absorbent structure and web materialsjoined together to form different components of the articles. Examplesof seams in absorbent articles which may use the bonding patternaccording to the disclosure are shown in FIGS. 5-7.

FIG. 5 shows a pant-type absorbent article 10 having a defined waistopening 11 and a pair of leg openings 12 and which are pulled onto thebody of the wearer by inserting the legs into the leg openings andpulling the article up over the waist. Examples of such pant-typeabsorbent article are pant diapers, training pants, swim pants, sanitarypants and incontinence pants worn by incontinent adults. The articlewill in the following be referred to as a “pant diaper”. The article hasa longitudinal direction y and a transverse direction x.

The pant diaper comprises a front body panel 13, which is the part ofthe pant diaper that in use is intended to extend over the stomach andfront hip area of the wearer. The article also comprises a back bodypanel 14, which is the part of the article that in use is intended toextend over the back and the rear hip area of the wearer. The crotchportion 15 of a pant diaper article is the part of the diaper that inuse is intended to extend through the wearer's crotch area, between thelegs.

An absorbent core 16 is disposed in the crotch portion 15 and extendsinto the front and back body panels 13 and 14. The absorbent core isdisposed between an inner coversheet 17 and an outer coversheet 18.

The term “inner coversheet” refers to the liquid permeable materialsheet forming the inner cover of the absorbent article and which in useis placed in direct contactwith the skin of the wearer. The innercoversheet can comprise a nonwoven material, e.g. spunbond, meltblown,carded, hydroentangled, wetlaid etc. Suitable nonwoven materials can becomposed of natural fibers, such as woodpulp or cotton fibres, man-madefibres, such as polyester, polyethylene, polypropylene, viscose, rayonetc. or from a mixture of natural and man-made fibres. The innercoversheet material may further be composed of tow fibres, which may bebonded to each other in a bonding pattern, as e.g. disclosed in EP-A-1035 818. Further examples of inner coversheet materials are porousfoams, apertured plastic films etc. The materials suited as innercoversheet materials should be soft and non-irritating to the skin andbe readily penetrated by body fluid, e.g. urine or menstrual fluid. Theinner coversheet may further be different in different parts of theabsorbent article.

The “outer coversheet” refers to the material forming the outer cover ofthe absorbent article. The outer coversheet may be the same or differentin different parts of the absorbent article. At least in the area of theabsorbent core the outer coversheet comprises a liquid imperviousmaterial a thin plastic film, e.g. a polyethylene or polypropylene film,a nonwoven material coated with a liquid impervious material, ahydrophobic nonwoven material, which resists liquid penetration, or alaminate of a plastic film and a nonwoven material. The outer coversheetmaterial may be breathable so as to allow vapour to escape from theabsorbent core, while still preventing liquids from passingtherethrough. Examples of breathable outer coversheet materials areporous polymeric films, nonwoven laminates of spunbond and meltblownlayers and laminates of porous polymeric films and nonwoven materials.Preferably, the outer coversheet comprises a nonwoven material on atleast the garment-facing surface thereof.

The “absorbent core” is the absorbent structure disposed between the twocoversheets of the absorbent article in at least the crotch regionthereof. The absorbent core can be of any conventional kind. Examples ofcommonly occurring absorbent materials are cellulosic fluff pulp, tissuelayers, highly absorbent polymers (so called superabsorbents), absorbentfoam materials, absorbent nonwoven materials or the like. It is commonto combine cellulosic fluff pulp with superabsorbent polymers in anabsorbent core. Superabsorbent polymers are water-swellable,water-insoluble organic or inorganic materials capable of absorbing atleast about 20 times their own weight of an aqueous solution containing0.9 weight percent of sodium chloride. Organic materials suitable foruse as superabsorbent materials can include natural materials such aspolysaccharides, polypeptides and the like, as well as syntheticmaterials such as synthetic hydrogel polymers. Such hydrogel polymersinclude, for example, alkali metal salts of polyacrylic acids,polyacrylamides, polyvinyl alcohol, polyacrylates, polyacrylamides,polyvinyl pyridines, and the like. Other suitable polymers includehydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch,and isobutylene maleic anhydride copolymers and mixtures thereof. Thehydrogel polymers are preferably lightly cross-linked to render thematerial substantially water insoluble. Preferred superabsorbentmaterials are further surface cross-linked so that the outer surface orshell of the superabsorbent particle, fibre, flake, sphere, etc.possesses a higher crosslink density than the inner portion of thesuperabsorbent. The superabsorbent materials may be in any form which issuitable for use in absorbent composites including particles, fibres,flakes, spheres, and the like.

A high liquid storage capacity is provided by the use of high amounts ofsuperabsorbent material. For an absorbent core comprising a matrix ofhydrophilic fibres, such as cellulosic fibres, and superabsorbentmaterial, the proportion of superabsorbent material is preferablybetween 10 and 90% by weight, more preferably between 30 and 70% byweight.

It is conventional for absorbent articles to have absorbent corescomprising layers of different properties with respect to liquidreceiving capacity, liquid distribution capacity and storage capacity.The thin absorbent bodies, which are common in for example baby diapersand incontinence guards, often comprise a compressed, mixed or layeredstructure of cellulosic fluff pulp and superabsorbent polymers. The sizeand absorbent capacity of the absorbent core may be varied to suitdifferent uses, such as infants or adult incontinent persons.

The absorbent core may further include an acquisition distribution layerplaced on top of the primary absorbent body, which is adapted to quicklyreceive and temporarily store discharged liquid before it is absorbed bythe primary absorbent core. Such acquisition distribution layers arewell known in the art and may be composed of porous fibrous wadding orfoam materials.

The front and back body panels 13 and 14 or those parts thereof that arelocated outside the absorbent core region may have different materialcomposition than the crotch portion 15. Thus according to one embodimentthe areas of the front and back body panels 13 and 14 which are locatedoutside the absorbent core region may be composed of for example alaminate material having a body facing side and a garment facing side,while a liquid impervious outer coversheet and/or a liquid perviousinner coversheet only is present in the absorbent core region. In otherembodiments the inner and outer coversheets are the same in the frontand back body panels 13 and 14 as well as in the crotch region 15.

The entire or part of the front and back body panels may be of elasticmaterial. The elastic web material may be in the form of elasticnonwoven materials, nonwoven materials which per se are inelastic, butwhich have been elastified by means of elastic threads etc., elasticlaminates composed of external layers of fibrous material and a middleelastic film layer.

The front and back panels 13 and 14 are joined along longitudinal sideedges so as to form side seams 19. The front and back panels 13 and 14can either be joined with the inner coversheets 17 of either the frontor back panel facing the outer coversheet 18 of the opposite panel. Insuch case the side seam will be in the same plane as the adjacentportions of the front and back panels facing inwards in the side seams,as is shown in FIG. 5. Alternatively they are joined with the innercoversheets of the front and back panels facing inwards, wherein theside seam 19 will protrude from the plane of the front and back panels.

The front and back panels 13 and 14 are joined along the side seams 19by a bonding pattern 4 according to an embodiment of the disclosure,comprising a main central bonding pattern 8 and two edge bondingpatterns 9.

An elastic waistband 20 is secured to the front and back panels 13 and14 along the waist opening. In its most common form the elasticwaistband 20 comprises a substantially non-elastic nonwoven materialthat is elasticized by elongate elastic members 21, such as elasticthreads or bands, contractably affixed between material layers, such asnonwoven materials. Alternatively the elastic waistband comprises anelastic nonwoven or an elastic film-nonwoven laminate. The elasticwaistband 20 is joined to the front and back panels 13 and 14 by abonding pattern 4 according to an embodiment of the disclosure

The leg openings 12 are also elasticized, said elastification is usuallyaccomplished by a plurality of elastic members 12 a, such as elasticthreads, which are contractably affixed between the outer and innercoversheets.

FIGS. 6 and 7 of the drawings show an embodiment of an absorbent garmentin the form of a diaper or incontinence guard 22 comprising a first bodypanel 23 and a second body panel 24, and a crotch portion 25 therebetween. An absorbent core 26 is disposed in the crotch portion 25 andextends into the first and second body panels 23 and 24. The absorbentcore 26 is disposed between an inner coversheet 27 and an outercoversheet 28.

The inner and outer coversheets and the absorbent core may be of thematerials mentioned above with respect to the pant diaper. The garmenthas a longitudinal direction y and a transverse direction x.

A pair of belt members 29 are attached to the waist portion of secondbody panel 24 and are intended to be wrapped around the waist of thewearer of the garment and fastened together by means of first fasteningmeans 30, for example a mechanical fastener, especially a hook fastenerof a hook-and-loop fastening means. The external surface of the oppositebelt member, especially if this comprises a fibrous nonwoven, mayfunction as a loop member.

A “hook-and-loop fastener” refers to complementary fastening meanshaving a “hook” portion and a “loop” portion and which are refastenable.The term “hook” as used herein refers to any element capable of engaginganother element, the so called “loop” portion. The term “hook” is notlimited to only “hooks” in its normal sense, but rather encompasses anyform of engaging elements, whether unidirectional or bi-directional. Theterm “loop” is likewise not limited to “loops” in its normal sense, butalso encompasses any structure capable of engaging with a “hook”fastener. Examples of “loop” materials are fibrous structures, likenonwoven materials. Hook-and-loop fasteners are for example availablefrom Velcro, USA.

Alternatively the first fastening means 30 is an adhesive fasteningmeans such as a tape tab, wherein the external surface of opposite beltmember 29 may be of a material to which the tape can adhere, as forexample described in WO 01/00129.

The width of the belt members 29 should be from 5 to 20 cm, preferablyfrom 7 to 15 cm. The belt members 29 are preferably made from a laminateof a carrier material, which forms the external surface of the belt, anda soft nonwoven, which forms the inside of the belt which is intended tobe in direct contact with the skin of the user.

A suitable nonwoven material can be a spunbond material of e.g.polypropylene or polyethylene fibres. Conjugate fibres may also be used.Another suitable nonwoven material is formed from a carded thermobondedmaterial of e.g. polypropylene, polyester or conjugate fibres.

The carrier material should be adapted to function as a receptionsurface for the fastening means 30. In case the fastening means is ahook fastener a nonwoven material may be used as a carrier material. Incase the fastening means 30 is a tape tab, a plastic film is suitable ascarrier material.

The first body panel 23, which normally is the front body panel, is thenpassed between the legs of the wearer and fastened to the outside of thebelt members 29 by means of second fastening means 31 provided at thelateral edges of the waist portion of the front panel 23. These secondfastening means 31 are mechanical fasteners, such as hook fasteners, oradhesive tape fasteners.

Each belt member 29 comprises at its proximal end adjacent the firstbody panel 24, an elastic region 29 a. Said elastic region 29 a may bein the form of an elastic web material such as an elastic film, anelastic nonwoven, an elastic laminate or the like. The elastic laminatemay be a laminate between two or more nonwoven layers, two or more filmlayers or a combination of film and nonwoven layers.

Examples of elastic laminates suitable for forming said elastic regions29 a are any elastic laminate known in the art. One group of elasticlaminates are so called “stretch-bonded” laminates, in which the elasticlayer is stretched in at least one direction before laminating it withone or more inelastic layers. After the tension is removed from theelastic layer it can freely retract to its untensioned state, and theinelastic layer(s) laminated thereto become gathered, giving athree-dimensional puckering.

Another group of elastic laminates are so called “neck bonded”laminates, which refer laminates in which an elastic material is bondedto a non-elastic material while the non-elastic member is extended underconditions reducing its width or necked. “Neck bonded laminate” refersto a composite material having at least two layers in which one layer isa necked, non-elastic layer and the other layer is an elastic layer. Thelayers are joined together when the non-elastic layer is in an extendedcondition.

A further group of elastic laminates are disclosed in for exampleWO/047488, in which inelastic nonwoven layers are laminated to anelastic film layer, and the laminate is stretched above the point offailure of the nonwoven materials, so that the inelastic layers break.

Examples of elastic laminates are described in EP-B-0 646 062, WO98/29251, WO 03/000165 and U.S. Pat. No. 5,226,992. Examples ofcommercially available elastic laminates are Fabriflex 306 from Tredegarand PK 6358 from Nordenia.

The elastic regions 29 a preferably have an elasticity of at least 30%as measured in the elasticity test as described below.

Alternatively the elastic regions 29 a comprises one or more elasticthreads or strips contractably affixed between web material layers.

In an alternative embodiment only one belt member 29 is provided with anelastic region 29 a.

A waist elastic member 32 extends in transverse direction, x, along atleast part of the waist portion of each body panel 23 and 24. The waistelastic member may be an elastic web material such as an elasticlaminate, an elastic film or the like contractably attached between theinner and outer coversheets, to the external side of the outercoversheet or to the wearer facing side of the inner coversheet.Alternatively it comprises two or more elastic threads or stripscontractably affixed between the outer and inner coversheets.

The leg openings are also elasticized, said elastification is usuallyaccomplished by a plurality of elastic members 33, such as elasticthreads, which are contractably affixed between the outer and innercoversheets.

The elastic region 29 a is bonded to the respective belt member 10and/or to the first body panel 24 side edge by a bonding pattern 4according to an embodiment of the disclosure.

Elasticity Test

The method measures how an elastic material behaves at repeated load andunload cycles. The sample is stretched to a predetermined elongation anda cyclic movement between 0 and said predetermined elongation isperformed. Desired load and unload forces are recorded. The permanent,i.e. remaining, elongation of the relaxed material is measured.

A tensile tester, Lloyd LRX, able to perform cyclic movements andequipped with a printer/ploffer or software presentation is used. Thesample is prepared by cutting it to a width of 25 mm and a length thatis preferably 20 mm longer than the distance between the clamps in thetensile tester.

The tensile tester is calibrated according to the apparatusinstructions. The parameters needed for the test (load and unloadforces) are adjusted to:

-   -   Crosshead speed: 500 mm/min    -   Clamp distance: 50 mm    -   Preload: 0.05 N

The sample is placed in the clamps according to the marks and it is madesure that the sample is centred and fastened perpendicularly in theclamps. The tensile tester is started and three cycles between 0 and thepredetermined elongation, equal to the highest defined 1^(st) load, areperformed. Before the last cycle, the sample is relaxed for 1 minute,then the permanent elongation is measured by stretching the sample untila force of 0.1 N is detected and the elongation is read.

The permanent elongation after relaxation should be less than 10% and ismeasured by the method above. Thus an elasticity of 30% is defined asthat the web material should have a permanent relaxation afterelongation of less than 10% after being exerted to an elongation of 30%in the tensile tester above. An elongation of 30% means an elongation toa length that is 30% longer than the initial length of the sample.

Although only a few exemplary embodiments of bonding patterns andapplications for the bonding pattern according to the disclosure havebeen described in detail above, those skilled in the art will readilyunderstand that many modifications are possible both with respect to theconfiguration of the bonding pattern and applications therefore.

The invention should not be considered as limited by the abovedescription; rather the scope and limitations of the invention aredefined by the enclosed granted claims and equivalents there.

1. A seam joining together at least first and second web materials, atleast one of which comprising heat fusible material, the first webmaterial having a side edge overlapping with a side edge of the secondweb material, wherein an overlapped portion is formed where said webmaterials overlap, said web materials in said overlapped portion beingbonded together in a bonding pattern extending over at least a part ofthe overlapped portion to form said seam, said overlapped portion havinga longitudinal and transverse direction and a pair of longitudinal sideedges defined by said overlapping side edges of the web materials,wherein said bonding pattern comprises a main bonding pattern extendingin longitudinal direction along at least a part of the overlappedportion, and at least one edge bonding pattern extending in longitudinaldirection along and adjacent at least a part of at least one of saidside edges, wherein said main bonding pattern is defined in longitudinaldirection by an outer limiting margin and said edge bonding pattern isdefined in longitudinal direction by an inner limiting margin, whereinthe distance between said outer and said inner limiting margin is atleast 1.5 mm and the bonded area of said edge bonding pattern(s)occupies no more than 30% of the total bonded area of the centralbonding pattern plus the bonded area of the edge bonding pattern(s). 2.A seam as claimed in claim 1, wherein said edge bonding pattern occupiesat least 5%, of the total bonding area occupied by the combined mainbonding pattern and edge bonding pattern.
 3. A seam as claimed in claim1, wherein said edge bonding pattern occupying no more than 25% of thetotal bonding area occupied by the combined main bonding pattern andedge bonding pattern.
 4. A seam as claimed in claim 1, wherein said edgebonding pattern is in the form of a plurality of small bonding siteseach having an area of no more than 4 mm².
 5. (canceled)
 6. A seam asclaimed in claim 1, wherein said bonding pattern comprises two edgebonding patterns, one on each side of the main bonding pattern.
 7. Aseam as claimed in claim 6, wherein the distance between the innerlimiting margins of the two edge bonding patterns is between 25 and 95%of the width of the seam overlapped portion in transverse direction. 8.A seam as claimed in claim 1, wherein the width of the overlappedportion in transverse direction is between 8 and 30 mm.
 9. A seam asclaimed in claim 1, wherein said main bonding pattern has a bondingdensity of between 10 and 80%.
 10. A seam as claimed in claim 1, whereinsaid edge bonding pattern has a bonding density of at least 2% and nomore than 60%.
 11. A seam as claimed in claim 1, wherein said webmaterials have basis weight between 25 and 130 g/m².
 12. A seam asclaimed in claim 1, wherein at least one of the web materials is anelastic material.
 13. A seam as claimed in claim 1, wherein the seam islocated in the same plane as the web materials that are joined together.14. A personal care absorbent article comprising an absorbent structureand first and second web materials comprising heat fusible materialjoined together at a seem formed by a bonding pattern as claimed inclaim
 1. 15. A personal care absorbent article as claimed in claim 14,wherein said personal care absorbent article is a pant-like garmentcomprising a first body panel, a second body panel and a crotch portionthere between, said first and second body panels being joined togetherin an overlapped manner to form side seams joined by the bondingpattern.
 16. A personal care absorbent article as claimed in claim 14,wherein said personal care absorbent article is a pant-like garmentcomprising a first body panel, a second body panel and a crotch portionthere between, said first and second body panels being joined togetherto form side seams and further being provided with an elastic waistband,said waistband being joined to the first and/or second body panels in anoverlapped manner to form said seam defined by the bonding pattern. 17.A personal care absorbent article as claimed in claim 14, wherein saidpersonal care absorbent article is an absorbent garment comprising afirst body panel, a second body panel and a crotch portion here between,each of said first and second body panels having a waist portion, saidgarment further being provided with opposed laterally extending beltmembers attached to the waist portion of the second body panel and beingadapted to be wrapped around the waist of the wearer of the garment andfastened together by means of first fasteners, the first body panel atits waist portion being provided with second fasteners adapted to befastened to the belt members, in such a way that the garment will assumea pant-like shape, at least one of the belt members comprises an elasticregion located at the proximal end of said belt member adjacent thewaist portion of the second body panel, said elastic region being joinedto the rest of the respective belt member and/or to the second bodypanel in an overlapped manner to form said seam defined by the bondingpattern.